whats multimeter

and insert it to facilitate debugging. If it is difficult to purchase a card holder, you can directly use an IC seat. Connect the cable with a string of 9 to 9 male and a mother. Note that there are two or three cross ports on the market. It is best to use a multimeter to check whether there is a one-to-one correspondence. If you do not have a serial line, you can also split an old-fashioned serial port with the mouse, as long as the two ends are con

Faults and tests:A power user in Dalian has a site that has a slow access speed and is interrupted from time to time. The network adapter has been replaced and the PC settings have been checked. The problem cannot be determined. In addition, the problem still cannot be solved by changing the network cable to different ports of the switch. Other users connected to the vswitch are normal. After the user purchases the network multimeter, The NT-IL (onlin

parallel port 2-pin, 9-pin PB8 (RESET) connect the 480 euro resistor to the parallel port and connect 10 thousand euro resistor to the positive pole (VCC), 15 feet PD5 Series 1 thousand euro resistor and a light emitting diode (attention direction) rear Power Supply positive pole (VCC), 18 feet XTAL2, 19 feet XTAL1 connected crystal oscillator and vibration capacitor (standard method), oscillating circuit GND, microcontroller 20 feet (GND) and the parallel port 18-pin (GND) is connected to the

should be less than that of pdsm and a certain margin is left.IDSM-maximum leakage source current. It is a limit parameter. It refers to the maximum current allowed to pass between missing sources during normal operation of the FET. The operating current of the FET should not exceed IDSM.4. Pin identification of the junction FET:Determine the gate G: dial the multimeter to the r × 1k file, use the negative pole of the

be measured includes the maximum, minimum, and average values of various currents. The average value is the focus of Power Consumption debugging, while the maximum and minimum values are especially important for the stability of the entire board. For example, the maximum current on the-board processor is 600mA, the minimum value is 100mA, and the average value is 200mA. The maximum value on the B-board is 400mA, the minimum value is 150mA, and the average value is 200mA, the two Board B must b

. First, use a multimeter to check whether the voltage at the five output ends is normal. The result shows that the positive and extreme values of the power supply filter capacitor c117 are 0 V, while the normal values are about 5 V, which is obviously abnormal, this indicates that the peripheral circuit components are short or open. The method of measuring current is used to find that the l105 current is very small, and it is further suspected that t

finger fetch, many CPUs currently use commands from spiflash at the earliest, but some CPU still use the CPU from the lpcflash. Some motherboard, these are set through a jumper, so the idea is required during debugging: if it is from the SPI/lpcflash area, make sure that the flash chip of the corresponding model is placed in the correct flash location. Otherwise, the specified flash chip cannot be obtained. BIOS chip: The BIOS chip may fail to boot properly after the system is powered on due t

whether the connection is good. You can use a multimeter to measure the connection. Place the Multimeter in the resistance position of x10, and contact one watch needle of the wanzhi beads with the corresponding core wire at the other end of the network cable, another 10 thousand use the table pen contact information module card into the corresponding color core line of the card trough edge note not contac

So how to master the quality of these media to ensure smooth transmission of information, you need to rely on the verification of the Cable Testing Instrument. In addition, more than 90% of the network faults are caused by cable link problems, but these problems can not be checked in the shortest time only by visual or multimeter. During network construction, you must test the cable using a regular tester. In general, the network card will not strike

, such as servers, switches, and routers, resulting in paralysis of the entire network. 1. Site-Level Test By checking physical connectivity, connection matching, protocol matching, and data sending and receiving correctness, this test solves most of the problems that a single site cannot connect to the network. Generally, the cabling system of the network should undergo a comprehensive test at the certification level. No fault affecting connection and communication will occur in special cases.

chips. When debugging a driver, in addition to fully understanding the data sheet of the chip, and in the process of software height, we also need to see whether the signal level we expect to occur on the chip. For example, when we write the driver, we need to write the I/O port to operate the peripheral chip, when writing the corresponding I/O port, we know that the corresponding chip signal should be valid, sometimes we need to verify whether the expected occurrence, which requires an oscillo

Bluetooth serial port out of the problem, only can not receive, the baby also do not know where the reason. Every time you lose a lost, down to the board found can not be used. And I don't know why. Silly don't pull a few look at the program, look for problems. Watch it for a week. Later, the laboratory students with a multimeter!! The problem with the test is hardware. Multimeter in the baby here is to do

IC 2003 Drive RelayThe left figure 1~7 is the signal input (in), the 10~16 is the output signal (out), and the 8 and 9 are IC power supplies. The diagram on the right is the inner schematic of the integration block.2.1 Simple introduction of working principleAccording to the input and output characteristics of IC Driver 2003, it is referred to as "drive" "inverter" "amplifier" and so on, now frequently used model: TD62003AP. When the 2003 input is high, the corresponding output is low, the rela

probes. The data that needs to be measured has the maximum, minimum, and average values for each circuit. The average value is the focus of power debugging, and the maximum and minimum values are particularly important for the stability of the whole board. For example, a board processor end current maximum is 600mA, the minimum is 100mA, the average is 200mA, and the same B board maximum is 400mA, the minimum value is 150mA, the average is also 200mA, these two board B board will certainly be

The method for determining whether a FET is good or bad is totally different from that of a transistor. The following describes how to determine whether a FET is good or bad: 1. the multimeter is equipped with a diode; 2. the red pen is connected to d pole, and the black pen is connected to S pole. In turn, the quantity is connected to a pressure drop of V; 3. the red pen is connected to the G pole, and the black pen is connected to the S pole, but th

a computer or a USB device. We can use other USB devices to test whether the computer is faulty.If it is a computer problem. Is your computer damaged by viruses. Whether the USB driver is installed properly or the version is not compatible. There is no software conflict (first solve the Software Problem). Generally, a prompt is prompted to install the driver.If it is a computer hardware problem. We first use A multimeter to measure the four USB lines

PreparationI didn't buy the original board. I purchased the compatible board from the authorized supplier. The compatible board has some changes.In order to connect the computer with the source board and the compatible board, you not only need to connect the cable, but also need to download the corresponding driver for the compatible board I purchased to use USB cable connection, the driver depends on the compatible board. Contact the supplier. Note that different drivers are required for differ

bridge, forcibly boot or abnormal shutdown, there is the phenomenon of intense hair hot. When using a multimeter to measure whether there is a short-circuit, first disconnect the power supply, dial out the ATX power cord. Then the multimeter to the diode position, Red pen grounding, black table pen to test points, we call it the measurement of the ground resistance. 1. Measure the 3.3V on the ATX power s

The motherboard leakage Solution method: In general, the motherboard is now a bad power supply heart slice is very likely, the power supply heart piece is broken, the CPU generally no temperature, at this time you can use digital multimeter diode gear measuring inductance and ground, if the multimeter is called a long word, power supply heart is good, if the inductor to the ground short-circuit, the mother

parameter. After dealing with the fault, we should make clear the cause of the fault, draw up the corresponding countermeasures, avoid the recurrence of similar failures as far as possible, and record the network management log for future reference and accumulate operation and maintenance experience. 2.2 General wiring troubleshooting common diagnostic tools General wiring Troubleshooting common diagnostic tools include: Hardware troubleshooting tools, software troubleshooting tools, as well